As safety consciousness in the use of electrical tools has increased over the years key-operated electrical switches have performed an important function by disabling the switch that controls the motor circuit to drive such a tool while the key is removed from the switch. The rocker type key-operated switch of the present applicant's U.S. Pat. No. 3,632,914 issued Jan. 4, 1972, and owned by the assignee of the present invention and application has played a significant commercial role in that respect. Other U.S. patents to the present applicant and to said assignee on rocker type key-operated switches are U.S. Pat. No. 3,678,229 issued July 18, 1972, and U.S. No. 4,230,917 issued Oct. 28, 1980. The switch of each such patent is normally mounted on the tool itself or on equipment for the tool and connected with the motor driving such tool for control of that motor circuit. However, there has also been a need for such a switch for motor driven electrical equipments that do not have this lockable protection, and might even need a portable switch for simply controlling the motor circuit, or for both operating the motor circuit and locking the switch against such operation therewith, as though such a switch had been originally provided with the equipment. That need is provided in the present invention as a portable electrical switch unit adapted for ready mounting in many places in connection with the equipment to be served, connectible by an extension cord to a source of electricity and having an electrical outlet therewith controlled by such switch into which the motor for the tool can be plugged and thereby energized with the switch in "On" position and disabled in "Off" position with the key removed.
It is an object of this invention to provide a sturdy and low cost portable unit having a rocker type key-operated switch therewith, an outlet with said unit electrically connected to and controlled by said switch to accommodate the cord and plug from the motor operating a tool, and an extension cord with said unit that is also electrically connected to said switch for connection in turn to an electrical source for the purpose of providing a circuit at said outlet controlled through said switch.
A further object is to provide such a portable unit wherein the elements of a switch and the elements of an electrical outlet for the unit are mounted on and utilize the structure of a molded base of insulating material covered by a member of insulating material which also cooperates in the assembly of the switch and the electrical outlet on such base and the handling and use of such portable unit, as well as completing a housing with said molded base.
A feature of the portable unit of this invention is that an extension cord positively gripped by and maintained in the assembled insulating base and cover members for such unit can be plugged into a so-called hot or live electrical outlet, and through an electrical key-lockable switch in the unit an outlet or receptacle likewise mounted and maintained in the housed structure can be turned on or off depending upon the position of the switch. When the switch is in off position with the key removed no unauthorized person can energize the outlet or receptacle in the unit, nor can the circuit through such outlet be turned on inadvertently, thus providing maximum protection against an improper turning on of a tool connected into such outlet of the portable unit.
The actuating structure for the switch includes a carrier and a rocker each pivotally mounted on the base with a common axis and pivotable independently of one another when unlocked and pivotable together when they are connected by the key, corresponding to such structure shown and described in the U.S. Pat. No. 3,632,914 which is cross-referenced herein for such structure and operation. In order to provide a sturdy and low cost housing for the complete switch and the complete outlet or receptable portion, the unit has a molded base of insulating material supporting stationary electrical contacts for the switch and for stationary receptable tabs in the outlet to receive the blades of a plug to be connected into such outlet in the usual manner to supply electricity for a motor. The wires for the extension cord for the portable unit are positioned in passageways or channels molded in such base, and the cord is gripped and maintained in position as it enters the base area by corresponding half or approximately half apertures and projections having the resiliency of the molded material. Barriers are also provided in the molded cover which fit into position around the receptacle contacts for the outlet and support such contacts as the blades of a plug are inserted therein.
A bridging contact for the switch moves logitudinally and slidingly on stationary contacts which are maintained on the molded insulating material base when the carrier and rocker of the switch are connected and movable into "On" or "Off" positions for corresponding operativeness or inoperativeness of the circuit to said outlet or receptacle in the unit.